In the completion of oil wells which traverse earth formations, a drilled borehole is lined with one or more strings to pipe called "liners" where each liner is cemented in place with respect to the borehole by an annulus to cement. To cement the liner in the borehole the liner or string of pipe is lowered into the drilled open borehole by means of a liner hanger setting tool and string of pipe used to lower the liner hanger to the position in a casing or liner where the liner hanger is set. The liner hanger is typically set at the lower end of a string of casing or another liner and extends a liner through an open borehole where the liner extends to a location near the bottom of the open borehole. At the open end of the string of pipe is a float shoe and typically two or three pipe joints above the cementing shoe is a float collar which contains a back pressure valve. The float collar typically is a short sub with precision machined threads at each end for coupling in a string of pipe and the collar has a configured interior wall surface which receives a drillable inserted assembly which has a one way check valve. The float collar is an expensive item to manufacture and utilize and the present invention involves a structure which can be disposed within the end of an ordinary joint of casing or liner and mechanically actuated by a setting tool to provide a float valve insert into the end of the casing or liner.